In response to demands for reduction in the weight of an automobile or airplane in recent years, studies have been conducted to replace metal parts with resin parts. Especially, recently, as techniques for reinforcing resin parts by use of carbon fibers progress, attempts to use a resin sheet into which carbon fibers are kneaded in a floor panel, pillar or the like of an automobile have been made.
Such a carbon fiber-containing resin sheet is preliminarily heated and softened in a heating furnace, and then press-molded into a desired shape in a pressing device. However, this heating temperature is higher than that at which a carbon fiber-containing resin sheet is drawn down, and thus the carbon fiber-containing resin sheet easily deforms in the course of carrying the resin sheet from the heating furnace to the pressing device. Such deformation easily causes misalignment of the feeding position to the pressing device, resulting in the possibility that a dimensional error may occur in a molded article.
Conventionally, structures using a sheet holding frame comprising a plurality of puncture needles, as described in JP11-292362 A, are known as those of soft sheet carrying apparatuses. However, in this case, there has been a problem that needle holes are formed in the entire circumferential edge part of a sheet, and thus that the circumferential edge part must be finally cut off, thereby causing a reduction in material yield. Especially, due to very high cost of a carbon fiber-containing resin sheet, this problem cannot be ignored.
A technique of laminating a protective film such as a polyimide film on a carbon fiber-containing resin sheet to prevent deformation during carrying has also been developed. However, in this case, the polyimide film must be removed from a product after press-molding, thereby causing an extra step. Further, there is a problem that an extra cost is required since the polyimide film is disposable.